Choosing pipes for a water-heated floor: Tips and Instructions + Video

Choosing pipes for a water-heated floor: Tips and Instructions + Video To provide comfort in your home, one of the solutions is to equip a water floor heating, so it is important to decide in advance which pipes choose for a water-heated floor.

This floor helps to distribute heat evenly throughout the house, unlike electric.

Also, a water-heated floor does not require large operating costs.

Therefore, more and more often water heated floors began to be used, besides, they became an independent source of heat in houses.

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Properties of pipes for underfloor heating

The durability and quality of a water floor system is directly dependent on materials and installation.

To make the choice of pipes for the thermal water floor correct, we have written this article and will analyze the selection features further.

And the installation of water heating pipes is best left to specialists. And so on, consider what pipes should be for a warm water floor.

Choosing pipes for a water-heated floor: Tips and Instructions + Video


Positive qualities in aquatic Heated floors are more than enough.

Water heated floors have the following positive qualities :

  1. Efficiency;
  2. Uniform heating;
  3. Durability;
  4. Possibility to regulate temperature;
  5. Lack of heating radiators.

Heating with a water-heated floor is easier to organize in a private house, but in a multi-storey building such heating is very difficult.

In the latter case, you will need to reconstruct an existing system or install your own electric boiler, this is necessary so as not to disrupt the heating of the entire building and not take heat from your neighbors.

Requirements for pipes

The durability and reliability of a water-heated floor depends heavily on pipes that will remain intact under the screed layer for many years.

The following requirements are imposed on pipes :

  1. Choosing pipes for a water-heated floor: Tips and Instructions + Video Ability to withstand changes in temperature and pressure. For a warm floor, pipes for hot heating are not suitable in any way.

    Be sure to choose pipes only for a water heated floor and companies that give a guarantee of fifty years or more;

  2. The pipes must have good insulation and tightness, because the system must be protected from oxidation;
  3. Stability bending and elasticity. When installing, the pipes are bent so that the floor warms up evenly and for this reason they should not break and crack when the pipe is bent;
  4. A suitable pipe diameter should be 16 -18 millimeters, in this case the floor height will hardly increase and disappear normal hydraulic equipment of the system;
  5. The expansion coefficient should be 0.25 mm / mK and the thermal conductivity should be 0.43 W / mK.

Types of pipes

For water floor heating systems use :

  • metal-plastic and polyethylene pipes,
  • very rarely copper,
  • corrugated steel,
  • polypropylene.

According to the norms, cast-iron pipes cannot be used for a warm water floor.

Reinforced-plastic pipes for warm water floors

Reinforced-plastic pipes are very popular. They are considered durable and also have good performance.

Choosing pipes for a water-heated floor: Tips and Instructions + Video

Pipes made of metal-plastic have a multilayer structure. The layer on the inside is polyethylene, crosslinked by extrusion, which is responsible for the characteristics of the pipes.

Then comes a layer of aluminum, it is glued to the polyethylene with glue.

To prevent oxygen from penetrating inside the pipe and to contain linear contractions and expansions, aluminum foil is inserted into the pipe.

The foil layer should be 0.2-0.25 mm, it depends on the diameter.

Due to the fact that the foil is welded in a joint or overlap, a layer is released that has airtightness.

There is another layer of glue on top of the foil, which connects it to the protective layer of polyethylene, which is located outside.


This structure of metal-plastic pipes has a lot of advantages :

  • Pipes are flexible and able to keep their shape after bending ;
  • Good thermal conductivity, it is provided by a layer of aluminum. They also have resistance to damage and overgrowth, due to the use of polymer;
  • It is possible to mount such pipes without special equipment;
  • They serve for a very long time;
  • Withstand temperatures up to 1100 degrees, without changing their qualities;
  • They are resistant to corrosion and negative environments;
  • Low weight;
  • Excellent sound insulation.

Among the minuses is that they cannot be twisted and bent with respect to the axis, which must be remembered.

It is very important to take into account the property of the aluminum layer; it is damaged by repeated bending.

Cross-linked polyethylene pipes

Cross-linked polyethylene pipes are a competitor to metal-plastic pipes.

Choosing pipes for a water-heated floor: Tips and Instructions + Video

The main quality of the product is the quality of the seam, which is judged by the density of the stitching. The optimal value is 60-85%.

Processing is done in different ways :

  1. When crosslinking with peroxide occurs, a density of 75% is obtained.

    These pipes are marked as PE-Xa;

  2. When crosslinking is done with silane, the density is 65%;
  3. Irradiation with an electron flow in a magnetic field, the crosslink density is up to 60%.

There are the following pipe markings :

  • HDPE - pipes with very high density;
  • MDPE - pipes have medium density;
  • LDPE pipes are of low density.
  • Positive qualities of these pipes:
  • Withstands temperatures up to 1200 degrees;
  • They are resistant to pressure and temperature changes;
  • The pipes are lightweight, also have a normal internal section with a small diameter;
  • Strength;
  • Good flexibility;
  • Ease of installation;
  • Low price.

Negative qualities :

  • It is necessary to fix the pipe well during installation. To fix the pipe, use fittings or a special substrate, and to fix the pipes in the desired position, use a very large amount of fasteners;
  • When pipes are installed, they are easily damaged, for this reason, you need to work with them carefully;
  • Sewed polyethylene pipes are made with a diameter of ten to one hundred and ten millimeters and a length of two hundred meters.

Copper pipes for underfloor heating

Copper, in terms of performance, is an ideal material for equipping underfloor heating.

Choosing pipes for a water-heated floor: Tips and Instructions + Video

Positive qualities :

  • High strength. If you do not compare the strength of copper pipes with polymer analogs, then they are quite strong;
  • Durability;
  • Good heat transfer rates;
  • Small bending radius among all pipes;
  • Withstands temperatures up to three thousand degrees and pressure in the system up to four hundred atmospheres;
  • Copper pipes are not gas-permeable and resistant to corrosion and limescale.

Copper pipes also have some disadvantages :

  • Have a high price;
  • It is necessary to use special equipment and use during installation brass fittings for connection, this greatly increases the cost of installation.

Other types of pipes for warm water floor


These stainless pipes are used less often than copper ones, despite on a number of advantages.

Choosing pipes for a water-heated floor: Tips and Instructions + Video

These products have a long service life, as well as good thermal conductivity, excellent bend , durable, do not corrode. But these pipes are not very cheap.

The disadvantage of such pipes is the limited service life of rubber bands for sealing.

Polypropylene pipes

Polypropylene pipes are an order of magnitude cheaper than copper pipes, steel pipes and metal-plastic pipes, but for some reason they are not widely used.

Choosing pipes for a water-heated floor: Tips and Instructions + Video

Pipes marked PN25 are used for underfloor heating, they are reinforced with perforated aluminum foil.

The outer diameter of the pipe is from 21 to 78mm, and the wall thickness should be from 4 to 13mm.


Positive qualities :

  • Low price;
  • Withstand temperatures up to 95 degrees at an optimum temperature of 55 degrees in the underfloor heating system;
  • Great strength.


Negative qualities :

  • Very small bend radius, for this reason there is no possibility equip the heating system properly. The minimum bending radius of such a pipe is eight diameters, which means that pipes with a diameter of about 23 mm are spaced from each other at a distance of 368 mm, and this may not be enough for the floor to be evenly heated.If the warm floor will be used as an additional source of heat, then the use of polypropylene pipes is more than justified.

Installation of polypropylene pipes is done at temperatures above + 10- +15 degrees, but this does not always work.

Well, we told you about the pipes of the warm water floor and we hope that the information will be necessary for you. We wish you good luck and patience!